Reducing sugar-based sulfide scavengers and methods of use in subterranean operations

ABSTRACT

Improved methods and additives for eliminating or reducing concentrations of hydrogen sulfide or soluble sulfide ions for use in subterranean formations and fluids are provided. In one embodiment, the methods comprise: providing a treatment fluid comprising a base liquid and a sulfide scavenging additive comprising one or more reducing sugars; introducing the treatment fluid into at least a portion of a subterranean formation; and allowing at least a portion of the sulfide scavenging additive to interact with hydrogen sulfide or sulfide ions present in the treatment fluid to produce a precipitate comprising one or more sulfur species.

BACKGROUND

The present disclosure relates to fluids, additives, and methods for usein subterranean operations, and more specifically, to improved methodsand additives for eliminating or reducing concentrations of hydrogensulfide or soluble sulfide ions for use in subterranean formations andfluids.

Hydrocarbon producing wells may contain many different formation liquidsand gases such as methane, ethane, and other higher hydrocarbons, aswell as hydrogen sulfide, water, and other compounds. In order toevaluate the commercial value of a hydrocarbon producing well, or as anaid in operations and well planning, it is often useful to obtaininformation by analyzing the component concentrations of the producedfluid from a formation or an individual well. Numerous systems have beendeveloped to evaluate a downhole fluid composition and the relativecomponent concentrations in the downhole fluid.

Hydrogen sulfide (H₂S) is a very toxic, flammable, and pungent gas thatcauses numerous problems in various aspects of the oil and gas industry.H2S is extremely corrosive to metal, which may damage or destroy tubing,casings, or other types of well bore equipment. H₂S also presents healthrisks to operations personnel that may be exposed to H₂S gas at a wellsite or in processing of well bore fluids. Severe iron sulfide scalingmay also choke production, either in the production piping, perforationsor within the producing formation itself. Thus, it is typicallydesirable to reduce or eliminate sulfides from subterranean formationsand well bores, among other reasons, to control corrosion rates and toplan for safe development and production of the hydrocarbons.

The release of H₂ 5 gas can sometimes be controlled by maintaining thepH of the fluid containing H₂ 5 above 10. However, in many cases, it isnot practical or possible to maintain this level pH in a fluid forextended periods of time. Sulfide scavengers are often used to reactwith H₂ 5 and convert it to a more inert form. Conventional H₂Sscavengers include certain aldehydes, certain amine-based chemicals,triazines, copper compounds, hydrogen peroxide, zinc compounds, and ironcompounds. However, the reaction products of many of these compoundswith H₂ 5 are poorly soluble in treatment fluids and/or fluids in thewell bore, or may decompose, thereby releasing H₂S. Moreover, manyconventional sulfide scavengers themselves may have undesirableenvironmental and/or toxicity problems, and as such may be impracticalto use or prohibited altogether in certain circumstances and/orjurisdictions.

SUMMARY

The present disclosure relates to fluids, additives, and methods for usein subterranean operations, and more specifically, to improved methodsand additives for eliminating or reducing concentrations of hydrogensulfide or soluble sulfide ions for use in subterranean formations andfluids.

In one embodiment, the present disclosure provides a method comprising:providing a treatment fluid comprising a base liquid and a sulfidescavenging additive comprising one or more reducing sugars; introducingthe treatment fluid into at least a portion of a subterranean formation;and allowing at least a portion of the sulfide scavenging additive tointeract with hydrogen sulfide or sulfide ions present in the treatmentfluid to produce a precipitate comprising one or more sulfur species.

In another embodiment, the present disclosure provides a methodcomprising: providing a treatment fluid comprising a base liquid and asulfide scavenging additive comprising one or more reducing sugarschelated with one or more metal ions; introducing the treatment fluidinto at least a portion of a subterranean formation; allowing at leastone of the metal ions to interact with hydrogen sulfide or sulfide ionspresent in the treatment fluid to produce a first product comprising oneor more sulfur species; and allowing the reducing sugar to interact withhydrogen sulfide or sulfide ions present in the treatment fluid toproduce a second product comprising one or more sulfur species.

In another embodiment, the present disclosure provides a method oftreating a fluid comprising a first concentration of hydrogen sulfide orsulfide ions, the method comprising: adding a sulfide scavengingadditive comprising one or more reducing sugars to the fluid; andallowing at least a portion of the sulfide scavenging additive tointeract with at least a portion of the hydrogen sulfide or sulfide ionsin the fluid to reduce the concentration of hydrogen sulfide or sulfideions to a second concentration that is lower than the firstconcentration.

The features and advantages of the present disclosure will be readilyapparent to those skilled in the art. While numerous changes may be madeby those skilled in the art, such changes are within the spirit of thedisclosure.

BRIEF DESCRIPTION OF THE FIGURES

Some specific example embodiments of the disclosure may be understood byreferring, in part, to the following description and the accompanyingdrawings.

FIG. 1 illustrates an example of a well bore drilling assembly that maybe used in accordance with certain embodiments of the presentdisclosure.

While the present disclosure is susceptible to various modifications andalternative forms, specific example embodiments have been shown in thefigures and are herein described in more detail. It should beunderstood, however, that the description of specific exampleembodiments is not intended to limit the invention to the particularforms disclosed. On the contrary, this disclosure is to cover allmodifications and equivalents as illustrated, in part, by the appendedclaims.

DESCRIPTION OF PREFERRED EMBODIMENTS

The present disclosure relates to fluids, additives, and methods for usein subterranean operations, and more specifically, to improved methodsand additives for eliminating or reducing concentrations of hydrogensulfide or soluble sulfide ions for use in subterranean formations andfluids.

The fluids and sulfide scavenging additives of the present disclosuregenerally comprise one or more reducing sugars. The term “reducingsugar” is defined herein to include any saccharide that includes analdehyde functional group or can isomerize to form an aldehydefunctional group in basic solution. In certain embodiments, the fluidsand sulfide scavenging additives of the present disclosure may besubstantially free of compounds having aldehyde functional group priorto placement in basic solution. In certain embodiments, the reducingsugar may be chelated with a metal ion, such as iron. When added to afluid comprising a liquid, a chelated reducing sugar may interact withH₂S and/or sulfide ions present in the fluid to produce one or moresulfur species (e.g., metal sulfides (such as Fe₂S₃ and FeS) andelemental sulfur), inter alia, in the form of a precipitate that can beremoved from the liquid. In certain embodiments, this may beaccomplished without further oxidization of the metal ions.

Among the many potential advantages of the present disclosure, themethods and compositions of the present disclosure may, among otherthings, provide a means of reducing or eliminating concentrations ofhydrogen sulfide or soluble sulfide ions in fluids found and/or used insubterranean formations with significantly less risk of environmentaldamage and/or health and safety hazards. Such methods and compositionsmay be more compatible with regulatory requirements in variousjurisdictions. The sulfide scavenging additives of the presentdisclosure comprising one or more reducing sugars may be effective at awider range of pH levels (e.g., pH ranges above about 8) than othersulfide scavenging additives known in the art, and may reduce oreliminate concentrations of hydrogen sulfide or soluble sulfide ions influids more effectively. The methods and compositions of the presentdisclosure also may be more cost effective than other sulfide scavengingmethods and additives known in the art.

The reducing sugars used in the methods, fluids, and sulfide scavengingadditives of the present disclosure may comprise any reducing sugar (orcombination thereof) known in the art. Such reducing sugars may comprisemonosaccharides, disaccharides, polysaccharides, and/or combinationsthereof. Examples of reducing sugars that may be suitable for use incertain embodiments of the present disclosure include, but are notlimited to, glucose, glucosamine, acetyl glucosamine, fructose, sucrose,lactose, maltose, cellobiose, galactose, mannose, ribose, ribulose,xylose, lyxose, rhamnose, arabinose, erythrose, and/or combinationsthereof. In certain embodiments, the reducing sugars used in themethods, fluids, and sulfide scavenging additives of the presentdisclosure may have a molecular weight of from about 180 daltons toabout 360 daltons. The reducing sugar optionally may be chelated withany metal ion known in the art, including but not limited to iron, zinc,copper, nickel, manganese, and the like. Chelated reducing sugars thatmay be suitable for use in certain embodiments of the present disclosureinclude, but are not limited to, ferric fructose, ferrous sucrose, andthe like.

The sulfide scavenging additives used in the present disclosure mayexhibit, among other features, an enhanced ability to scavenge sulfidesas compared to conventional sulfide scavengers due, at least in part, tothe manner in which they react with sulfides and other components of thefluid. In particular, sulfide scavenging additives of the presentdisclosure that comprise one or more metal ions chelated with reducingsugars may exhibit a dual sulfide scavenging mechanism wherein the metalion and the reducing sugar each interact with hydrogen sulfide orsulfide ions to produce different products that may be precipitated orotherwise removed from of the fluid. The interaction of the metal ionswith hydrogen sulfide or sulfide ions may proceed according to one ormore reactions similar those discussed in paragraph [0015] below. Theinteraction of the reducing sugar with hydrogen sulfide or sulfide ionsmay involve the degradation of the reducing sugar and the reaction ofthose degradation products with hydrogen sulfide or sulfide ions.Alternatively, the reducing sugar may interact with hydrogen sulfide orsulfide ions to form an intermediate sulfur-containing compound, thesugar moiety in which may fragment to form other sulfur containingspecies. The chelation of the reducing sugar with the metal ion also mayinhibit the conversion of the metal ion to a metal hydroxide, leavingthe metal ion free to interact with and/or scavenge hydrogen sulfide orsulfide ions present in the fluid. However, the reaction mechanismsdisclosed herein are provided only as non-limiting illustrations of howthe sulfide scavenging additives of the present disclosure may react incertain embodiments, and are not intended to limit the scope of theclaims.

One example of a sulfide scavenging additive that may be suitable foruse in the present disclosure comprises ferric fructose. In thoseembodiments, the iron (III) ions in the ferric fructose may react withhydrogen sulfide to produce iron (III) sulfide (Fe₂S₃). Additionally,the iron (III) ions may be reduced by hydrogen sulfide to their iron(II) oxidation state, producing elemental sulfur (S⁰) (see Equation (1)below). The reduced iron (II) ion may react with additional hydrogensulfides to produce iron (II) sulfide (FeS) (see Equation (2) below).

H₂S+2Fe³⁺→S⁰+2Fe²⁺+2H⁺  (1)

H₂S+Fe²⁺→FeS+2H⁺  (2)

In this process, the overall result for the ferric ion in thisembodiment of the present disclosure may be expressed according toEquation (3) below:

2H₂S+2Fe³⁺→S⁰+2FeS+4H⁺  (3)

The elemental sulfur and iron (II) sulfide may form a precipitate in thefluid being treated, which may be removed from the fluid. Similarreactions may occur using metallic ions other than iron. In embodimentswhere divalent metallic ions are used, elemental sulfur may not beformed. In addition to the reactions above, the fructose may interactwith hydrogen sulfide or sulfide ions to produce various sulfur speciesthat may precipitate or be removed from the fluid being treated.

The reducing sugar (or chelated reducing sugar) may be added to orincluded in a fluid in any concentration that effectively eliminates orreduces by the desired amount concentrations of H₂S or sulfide ions thatare present or expected to be present in the fluid. For example, thereducing sugar may be added in a stoichiometric amount relative to theestimated amount of H₂ 5 or sulfide ions in the fluid. In certainembodiments, the reducing sugar may be present a fluid in aconcentration of about 0.1 to 5 pounds per barrel. As discussed below,an initial amount of the sulfide scavenging additives of the presentdisclosure comprising one or more reducing sugars may be added to afluid, and subsequently, additional amounts of the sulfide scavengingadditives of the present disclosure may be added to the same fluid. Thistechnique may be used, among other purposes, to increase and/or maintaina concentration of the reducing sugar that is sufficient to effectivelyeliminate or reduce by the desired amount concentrations of H₂S orsulfide ions in the fluid throughout the course of a given operation.

The additives of the present disclosure may be used in conjunction withany fluid, which may include, but are not limited to, treatment fluidsintroduced into a subterranean formation as well as fluids found in asubterranean formation (e.g., formation water, hydrocarbon fluids, etc.)and/or any combination thereof. The treatment fluids and formationfluids in the present disclosure generally comprise a base liquid, whichmay comprise any liquid known in the art, such as aqueous liquids,non-aqueous liquids, or any mixture thereof. Where the base liquidcomprises an aqueous liquid, it may comprise fresh water, salt water(e.g., water containing one or more salts dissolved therein), brine(e.g., saturated salt water), or seawater. Generally, the water can befrom any source, provided that it does not contain compounds thatadversely affect other components of the fluid. Where the base liquidcomprises a non-aqueous liquid, it may comprise any number of organicliquids. Examples of suitable organic liquids include, but are notlimited to, mineral oils, synthetic oils, esters, and the like. Incertain embodiments, the treatment fluids and/or formation fluids in thepresent disclosure may comprise emulsions (including invert emulsions),suspensions, gels, foams, or other mixtures of liquids with solidsand/or gases.

The fluids used in the present disclosure optionally may comprise anynumber of additional additives, including, but not limited to, salts,surfactants, acids, fluid loss control additives, gas, nitrogen, carbondioxide, surface modifying agents, tackifying agents, foamers, corrosioninhibitors, scale inhibitors, catalysts, clay control agents, biocides,friction reducers, antifoam agents, bridging agents, dispersants,flocculants, additional H₂S scavengers, CO₂ scavengers, oxygenscavengers, lubricants, viscosifiers, breakers, weighting agents,relative permeability modifiers, resins, particulate materials (e.g.,proppant particulates), wetting agents, coating enhancement agents, andthe like. A person skilled in the art, with the benefit of thisdisclosure, will recognize the types of additives that may be includedin the fluids of the present disclosure for a particular application.

The methods, fluids, and/or additives of the present disclosure may beused during or in conjunction with any subterranean operation wherein afluid is used or treated. In certain embodiments, the methods, fluids,and/or additives of the present disclosure may be used in the course ofdrilling operations. In these embodiments, the methods, fluids, and/oradditives of the present disclosure may be used to reduce or eliminateconcentrations of H₂S from a drilling fluid used in drilling a well orborehole, for example, in a hydrocarbon-bearing subterranean formationwhere H₂S is often encountered. Other suitable subterranean operationsmay include, but are not limited to, preflush treatments, afterflushtreatments, hydraulic fracturing treatments, sand control treatments(e.g., gravel packing), acidizing treatments (e.g., matrix acidizing orfracture acidizing), “frac-pack” treatments, well bore clean-outtreatments, and other operations where a treatment fluid may be useful.Such treatment fluids may include, but are not limited to, drillingfluids, preflush fluids, afterflush fluids, fracturing fluids, acidizingfluids, gravel packing fluids, packer fluids, spacer fluids, and thelike.

The reducing sugar may be provided in an additive in a solid form,liquid form (e.g., in solution of water or another solvent), or acombination thereof. The sulfide scavenging additives of the presentdisclosure may be added to a fluid by any means known in the art. Theadditive may be added to the fluid, for example, in the mud pit beforethe fluid has circulated or before the fluid contains any detectableamount of sulphur or H₂S, as a prophylactic measure against any H₂S thefluid may encounter downhole. In certain embodiments, the additive maybe added after the fluid has been circulating downhole and has alreadyencountered sulphur or H₂S and contains same. In certain embodiments,the amount of the additive added to the fluid may be controlled and/orvaried during the course of an operation based on, among other things,the amount of sulfur or H₂S detected in fluids exiting the well bore. Inthese embodiments, any system or technique capable of monitoring ordetecting sulfur or H₂S content in fluids exiting the well bore may beused. Moreover, the sulfide scavenging additives of the presentdisclosure may be added to a fluid in multiple portions that are addedto the fluid at separate intervals over a period of time. For example, afirst amount of a scavenging additive of the present disclosure may beadded to a fluid at one point in time in the course of a particularoperation. At a subsequent point during that operation, an elevatedamount of sulfur or H₂S may be detected exiting the well bore, at whichpoint a second amount of a scavenging additive of the present disclosuremay be added to the fluid based at least in part on the amount of sulfuror H₂ 5 detected.

The exemplary fluids and additives disclosed herein may directly orindirectly affect one or more components or pieces of equipmentassociated with the preparation, delivery, recapture, recycling, reuse,and/or disposal of the disclosed fluids and additives. For example, andwith reference to FIG. 1, the disclosed fluids and additives maydirectly or indirectly affect one or more components or pieces ofequipment associated with an exemplary wellbore drilling assembly 100,according to one or more embodiments. It should be noted that while FIG.1 generally depicts a land-based drilling assembly, those skilled in theart will readily recognize that the principles described herein areequally applicable to subsea drilling operations that employ floating orsea-based platforms and rigs, without departing from the scope of thedisclosure.

As illustrated, the drilling assembly 100 may include a drillingplatform 102 that supports a derrick 104 having a traveling block 106for raising and lowering a drill string 108. The drill string 108 mayinclude, but is not limited to, drill pipe and coiled tubing, asgenerally known to those skilled in the art. A kelly 110 supports thedrill string 108 as it is lowered through a rotary table 112. A drillbit 114 is attached to the distal end of the drill string 108 and isdriven either by a downhole motor and/or via rotation of the drillstring 108 from the well surface. As the bit 114 rotates, it creates aborehole 116 that penetrates various subterranean formations 118.

A pump 120 (e.g., a mud pump) circulates drilling fluid 122 through afeed pipe 124 and to the kelly 110, which conveys the drilling fluid 122downhole through the interior of the drill string 108 and through one ormore orifices in the drill bit 114. The drilling fluid 122 is thencirculated back to the surface via an annulus 126 defined between thedrill string 108 and the walls of the borehole 116. At the surface, therecirculated or spent drilling fluid 122 exits the annulus 126 and maybe conveyed to one or more fluid processing unit(s) 128 via aninterconnecting flow line 130. After passing through the fluidprocessing unit(s) 128, a “cleaned” drilling fluid 122 is deposited intoa nearby retention pit 132 (i.e., a mud pit). While illustrated as beingarranged at the outlet of the wellbore 116 via the annulus 126, thoseskilled in the art will readily appreciate that the fluid processingunit(s) 128 may be arranged at any other location in the drillingassembly 100 to facilitate its proper function, without departing fromthe scope of the scope of the disclosure.

One or more of the disclosed additives may be added to the drillingfluid 122 via a mixing hopper 134 communicably coupled to or otherwisein fluid communication with the retention pit 132. The mixing hopper 134may include, but is not limited to, mixers and related mixing equipmentknown to those skilled in the art. In other embodiments, however, thedisclosed additives may be added to the drilling fluid 122 at any otherlocation in the drilling assembly 100. In at least one embodiment, forexample, there could be more than one retention pit 132, such asmultiple retention pits 132 in series. Moreover, the retention pit 132may be representative of one or more fluid storage facilities and/orunits where the disclosed additives may be stored, reconditioned, and/orregulated until added to the drilling fluid 122.

As mentioned above, the disclosed fluids and additives may directly orindirectly affect the components and equipment of the drilling assembly100. For example, the disclosed fluids and additives may directly orindirectly affect the fluid processing unit(s) 128 which may include,but is not limited to, one or more of a shaker (e.g., shale shaker), acentrifuge, a hydrocyclone, a separator (including magnetic andelectrical separators), a desilter, a desander, a separator, a filter(e.g., diatomaceous earth filters), a heat exchanger, any fluidreclamation equipment, The fluid processing unit(s) 128 may furtherinclude one or more sensors, gauges, pumps, compressors, and the likeused store, monitor, regulate, and/or recondition the exemplary fluidsand additives.

The disclosed fluids and additives may directly or indirectly affect thepump 120, which representatively includes any conduits, pipelines,trucks, tubulars, and/or pipes used to fluidically convey the fluids andadditives downhole, any pumps, compressors, or motors (e.g., topside ordownhole) used to drive the fluids and additives into motion, any valvesor related joints used to regulate the pressure or flow rate of thefluids and additives, and any sensors (i.e., pressure, temperature, flowrate, etc.), gauges, and/or combinations thereof, and the like. Thedisclosed fluids and additives may also directly or indirectly affectthe mixing hopper 134 and the retention pit 132 and their assortedvariations.

The disclosed fluids and additives may also directly or indirectlyaffect the various downhole equipment and tools that may come intocontact with the fluids and additives such as, but not limited to, thedrill string 108, any floats, drill collars, mud motors, downhole motorsand/or pumps associated with the drill string 108, and any MWD/LWD toolsand related telemetry equipment, sensors or distributed sensorsassociated with the drill string 108. The disclosed fluids and additivesmay also directly or indirectly affect any downhole heat exchangers,valves and corresponding actuation devices, tool seals, packers andother wellbore isolation devices or components, and the like associatedwith the wellbore 116. The disclosed fluids and additives may alsodirectly or indirectly affect the drill bit 114, which may include, butis not limited to, roller cone bits, PDC bits, natural diamond bits, anyhole openers, reamers, coring bits, etc.

While not specifically illustrated herein, the disclosed fluids andadditives may also directly or indirectly affect any transport ordelivery equipment used to convey the fluids and additives to thedrilling assembly 100 such as, for example, any transport vessels,conduits, pipelines, trucks, tubulars, and/or pipes used to fluidicallymove the fluids and additives from one location to another, any pumps,compressors, or motors used to drive the fluids and additives intomotion, any valves or related joints used to regulate the pressure orflow rate of the fluids and additives, and any sensors (i.e., pressureand temperature), gauges, and/or combinations thereof, and the like.

Therefore, the present disclosure is well adapted to attain the ends andadvantages mentioned as well as those that are inherent therein. Theparticular embodiments disclosed above are illustrative only, as thepresent disclosure may be modified and practiced in different butequivalent manners apparent to those skilled in the art having thebenefit of the teachings herein. Furthermore, no limitations areintended to the details of construction or design herein shown, otherthan as described in the claims below. It is therefore evident that theparticular illustrative embodiments disclosed above may be altered ormodified and all such variations are considered within the scope andspirit of the present disclosure. While compositions and methods aredescribed in terms of “comprising,” “containing,” or “including” variouscomponents or steps, the compositions and methods can also “consistessentially of” or “consist of” the various components and steps. Allnumbers and ranges disclosed above may vary by some amount. Whenever anumerical range with a lower limit and an upper limit is disclosed, anynumber and any included range falling within the range is specificallydisclosed. In particular, every range of values (of the form, “fromabout a to about b,” or, equivalently, “from approximately a to b,” or,equivalently, “from approximately a-b”) disclosed herein is to beunderstood to set forth every number and range encompassed within thebroader range of values. Also, the terms in the claims have their plain,ordinary meaning unless otherwise explicitly and clearly defined by thepatentee. Moreover, the indefinite articles “a” or “an”, as used in theclaims, are defined herein to mean one or more than one of the elementthat it introduces. If there is any conflict in the usages of a word orterm in this specification and one or more patent or other documentsthat may be incorporated herein by reference, the definitions that areconsistent with this specification should be adopted.

What is claimed is:
 1. A method comprising: providing a treatment fluid comprising a base liquid and a sulfide scavenging additive comprising one or more reducing sugars; introducing the treatment fluid into at least a portion of a subterranean formation; and allowing at least a portion of the sulfide scavenging additive to interact with hydrogen sulfide or sulfide ions present in the treatment fluid to produce a precipitate comprising one or more sulfur species.
 2. The method of claim 1 wherein the base liquid comprises an aqueous liquid.
 3. The method of claim 1 wherein the treatment fluid comprises a basic solution.
 4. The method of claim 1 wherein the treatment fluid is substantially free of aldehydes other than aldehydes formed by the reducing sugars dissolved in the basic solution.
 5. The method of claim 1 wherein the pH of the treatment fluid is above
 8. 6. The method of claim 1 wherein one or more metal ions is chelated with the one or more reducing sugars.
 7. The method of claim 6 wherein the one or more metal ions interact with the hydrogen sulfide or sulfide ions to produce a precipitate comprising one or more metal sulfides.
 8. The method of claim 1 wherein the sulfide scavenging additive comprises ferric fructose.
 9. The method of claim 1 further comprising adding an additional amount of a sulfide scavenging additive comprising one or more reducing sugars to the treatment fluid after the treatment fluid has been introduced into at least a portion of a subterranean formation.
 10. The method of claim 1 wherein: the treatment fluid comprises a drilling fluid; and the method further comprises using the drilling fluid to drill at least a portion of a well bore penetrating at least a portion of the subterranean formation.
 11. A method comprising: providing a treatment fluid comprising a base liquid and a sulfide scavenging additive comprising one or more reducing sugars chelated with one or more metal ions; introducing the treatment fluid into at least a portion of a subterranean formation; allowing at least one of the metal ions to interact with hydrogen sulfide or sulfide ions present in the treatment fluid to produce a first product comprising one or more metal sulfides; and allowing the reducing sugar to interact with hydrogen sulfide or sulfide ions present in the treatment fluid to produce a second product comprising one or more sulfur species.
 12. The method of claim 11 wherein the base liquid comprises an aqueous liquid.
 13. The method of claim 11 wherein the pH of the treatment fluid is above
 8. 14. The method of claim 11 wherein the sulfur species in the second product are different from the metal sulfides in the first product.
 15. The method of claim 11 further comprising removing the first or second products from the treatment fluid in the form of a precipitate.
 16. The method of claim 11 further comprising adding an additional amount of a sulfide scavenging additive comprising one or more reducing sugars to the treatment fluid after the treatment fluid has been introduced into at least a portion of a subterranean formation.
 17. A method of treating a fluid comprising a first concentration of hydrogen sulfide or sulfide ions, the method comprising: adding a sulfide scavenging additive comprising one or more reducing sugars to the fluid; and allowing at least a portion of the sulfide scavenging additive to interact with at least a portion of the hydrogen sulfide or sulfide ions in the fluid to reduce the concentration of hydrogen sulfide or sulfide ions to a second concentration that is lower than the first concentration.
 18. The method of claim 17 wherein the fluid comprises an aqueous liquid.
 19. The method of claim 17 wherein the pH of the fluid is above
 8. 20. The method of claim 17 wherein the fluid is present in at least a portion of a subterranean formation. 